drm/omap: cleanup OMAP_BO flags

Reorder OMAP_BO flags and improve the comments.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: NJean-Jacques Hiblot <jjhiblot@ti.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191010120000.1421-5-jjhiblot@ti.com

include/uapi/drm/omap_drm.h

@@ -38,19 +38,20 @@ struct drm_omap_param {
 	__u64 value;			/* in (set_param), out (get_param) */
 };
 
-#define OMAP_BO_SCANOUT		0x00000001	/* scanout capable (phys contiguous) */
-#define OMAP_BO_CACHE_MASK	0x00000006	/* cache type mask, see cache modes */
-#define OMAP_BO_TILED_MASK	0x00000f00	/* tiled mapping mask, see tiled modes */
+/* Scanout buffer, consumable by DSS */
+#define OMAP_BO_SCANOUT		0x00000001
 
-/* cache modes */
-#define OMAP_BO_CACHED		0x00000000	/* default */
-#define OMAP_BO_WC		0x00000002	/* write-combine */
-#define OMAP_BO_UNCACHED	0x00000004	/* strongly-ordered (uncached) */
+/* Buffer CPU caching mode: cached, write-combining or uncached. */
+#define OMAP_BO_CACHED		0x00000000
+#define OMAP_BO_WC		0x00000002
+#define OMAP_BO_UNCACHED	0x00000004
+#define OMAP_BO_CACHE_MASK	0x00000006
 
-/* tiled modes */
+/* Use TILER for the buffer. The TILER container unit can be 8, 16 or 32 bits. */
 #define OMAP_BO_TILED_8		0x00000100
 #define OMAP_BO_TILED_16	0x00000200
 #define OMAP_BO_TILED_32	0x00000300
+#define OMAP_BO_TILED_MASK	0x00000f00
 #define OMAP_BO_TILED		(OMAP_BO_TILED_8 | OMAP_BO_TILED_16 | OMAP_BO_TILED_32)
 
 union omap_gem_size {